Arbor Networks, Inc.

Netscout Systems, Inc.

Sean O'Hara

Brian St Pierre

Alan Saqui

Steinthor Bjarnason

Andrew David Mortensen

Edmund J Gurney, Iii

Archana A Rajaram

Justin William Haddad

Kyle Barkmeier

Brantleigh Bunting

Bryan Beecher

Conner Jones

A computer implemented method system for obscuring the status of a network service provided by a network device. Received in a network monitoring device is network packet request message intended for a network device. The network monitoring device analyzes the received network packets request to determine whether the received network packet request is a DDoS network probe packet request. If the received packet request was determined to be a DDoS network probe packet requests, a response is generated and sent from the network monitoring device to the device that sent the DDoS network probe packet request indicating a faux degradation of service level for the intended network device.

System and method for obscuring status of a network service

An upstream network bridge connection request is received in a network device from first network component for connecting to a second network component. This upstream network bridge connection request is analyzed by the network bridge to determine if a network attack threat is associated with the client device requesting the upstream network bridge connection to the server device preferably by inspecting certain network metrics present in the downstream connection associated with the client device. If no, then a determination is made as to whether a preexisting upstream network bridge connection between the client device and the server device exists in a connection pool database. If yes, then the preexisting upstream network bridge connection is retrieved from the connection pool database and is implemented for creating an upstream network connection between the client and server devices.

Bridging between client and server devices using proxied network metrics

A computer-implemented method and a computer system are provided for selecting active or passive decryption mode when observing network traffic between a downstream client and an upstream server. The method includes selecting a decryption mode in an initial stage of setting up a secure session based on a determination of a most probable decryption mode based on decryption modes used for similar and/or past secure sessions, wherein the initial stage is when the client initiates a transport layer connection before the transport layer connection or the secure session is established. The method further includes validating the selected decryption mode at least once during the secure session based on whether the selected decryption mode is actually and/or is probably supported based on security algorithms supported by the client and/or server, and switching the decryption mode based on a result of validating the selected decryption mode.

Decryption of perfect forward secrecy (PFS) and non-PFS sessions

A system and method for providing network bridge upstream connections by a network device using proxied network metrics. An upstream network bridge connection request is received in a network device (e.g., a bridge device) from first network component (e.g., a client device) for connecting to a second network component (e.g., a network server device). This upstream network bridge connection request is analyzed by the network bridge to determine if a network attack threat is associated with the client device requesting the upstream network bridge connection to the server device preferably by inspecting certain network metrics present in the downstream connection associated with the client device. If no network attack threat is determined, then a determination is made as to whether a preexisting upstream network bridge connection between the client device and the server device exists in a connection pool database. If yes, then the preexisting upstream network bridge connection is retrieved from the connection pool database and is implemented for creating an upstream network connection between the client and server devices. If there is no preexisting upstream connection, then a new upstream network bridge connection is generated and implemented creating an upstream network connection between the client and server devices. And if the network bridge device determines a network attack threat was associated with the client device requesting the upstream network bridge connection request, then a new upstream network connection is created for coupling the client and server devices, which newly created upstream network connection is separate/segregated from any upstream connections preexisting in the connection pool database.

A computer method and system for mitigating Domain Name System (DNS) misuse using a probabilistic data structure, such as a cuckoo filter. Intercepted is network traffic flowing from one or more external hosts to a computer network, the intercepted network traffic including a DNS request that requests a Resource Record name in a DNS zone file. A determination is made as to whether the DNS request is requesting resolution at a protected DNS Name Server. A hash value is calculated for the requested Resource Record name if it is determined the DNS request is requesting resolution at the protected DNS Name Server. A determination is then made as to whether the calculated hash value for the requested Resource Record name is present in the probabilistic data structure. The DNS request is forwarded to the protected server if the requested Resource Record name is determined present in the probabilistic data structure.

System and method for DNS misuse detection

A computer method and system for scheduling packets for transmission over a network, via a gateway device having a packet buffer for temporarily storing packets intended for a network device. Upon reception of a packet in the gateway device intended for a network device, a determination is made as to whether the received packet is the start a new packet session for the network device. If yes, the packet is then caused to be forward to the intended network device. If no, then a determination is made as to whether drop the received packet contingent upon a determined current size of the packet buffer (e.g., does it exceed a predetermined packet size threshold value). If the packet is not dropped, then a determination is made as to whether mark the packet for network congestion control contingent upon the determined size of the packet buffer (e.g., does it exceed a predetermined network congestion packet size threshold value). The packet is then caused to be forwarded to the intended network device.

System and method for scheduling transmission of network packets

A method and system for aggregating into a unique aggregated group (AG), protection groups (PGs) that are possible classifications with at least a threshold probability for a same unique combination of IP addresses. The PGs and the unique combination of IP addresses are included in the AG. Each of the IP addresses of the unique combination of IP addresses have respective associated probabilities for each PG included in the AG. The method further includes selecting and providing for display AGs based on the probabilities associated with the respective IP addresses included in the AGs, and providing for display at least one interactive graphical element in association with each AG selected for display. User activation of one of the interactive graphical element accepts assignment of one or more selected IP addresses included in the AG to a selected one of the one or more PGs included in the AG.

Automated classification of network devices to protection groups

A system and computer-implemented method of managing botnet attacks to a computer network is provided. The system and method includes receiving a DNS request included in network traffic, each DNS request included in the network traffic and including a domain name of a target host and identifying a source address of a source host, wherein the translation of the domain name, if translated, provides an IP address to the source host that requested the translation. The domain name of the DNS request is compared to a botnet domain repository, wherein the botnet domain repository includes one or more entries, each entry having a confirmation indicator that indicates whether the entry corresponds to a confirmed botnet. If determined by the comparison that the domain name of the DNS request is included in the botnet domain repository, then the source address of the DNS request is stored or updated in an infected host repository and a control signal is output to cause any future network traffic from the source address to be diverted to an administrator configured address. Each source address stored in the infected host repository identifies a host known to be infected.

Real time management of botnet attacks

A computer method and system to determine one or more sub-groups of protected network servers for receiving common network filter settings for mitigating Denial of Services (Dos) attacks. Network traffic associated with the plurality of network servers is captured and collated for each of the plurality of network servers. The collated network traffic is then analyzed to determine a profile of one or more network services provided by each of the plurality of network servers. Each of the plurality of network servers is then tagged with one or more network services determined provided by each network server based upon analysis of the collated network traffic. Metadata is then determined from the collated network traffic that is associated with each of the plurality of network servers. A determination of sub-group clustering is made of one or more of the plurality of network servers contingent upon the one or more determined network service tags and the determined meta data associated with each of the plurality of network servers. Common DoS mitigation actions may then be prescribed for each of the determined sub-group clusters of network servers.

Clustering network servers for denial of service attacks

A method is provided for inspecting network traffic. The method, performed in a single contained device, includes receiving network traffic inbound from an external host that is external to the protected network flowing to a protected host of the protected network, wherein the network traffic is transported by a secure protocol that implements ephemeral keys that endure for a limited time. The method further includes performing a first transmission control protocol (TCP) handshake with the external host, obtaining source and destination data during the first TCP handshake, the source and destination data including source and destination link and internet addresses obtained, caching the source and destination data, and using the cached source and destination data to obtain a Layer-7 request from the external host to the protected host and to pass a Layer-7 response from the protected host to the external host.

Transparent inspection of traffic encrypted with perfect forward secrecy (PFS)

A method and system are provided for monitoring a protected network. The method includes, in a scoring phase, receiving a learned model having clusters of learning requests of learning network traffic observed during non-strain operation of the protected network, wherein each cluster has an associated characteristic learning response time. The method further includes receiving a score request to score a network service request of the network traffic, classifying the network service request with one of the clusters by comparing fields of the network service request to fields used for clustering the learning requests with the cluster, calculating a score based on the characteristic learning response times generated for the learned cluster to which the network service request is classified, and adjusting supportive handling of the network service request based on the score.

Scoring network traffic service requests using response time metrics

A method of monitoring network traffic for cryptojacking activity is provided. A request is received from a protected host. It is determined whether the request is a cryptocurrency request based on whether the request uses a protocol specified for requests belonging to the cryptocurrency communication. In response to a determination that the request is a cryptocurrency request for the cryptocurrency, a second request is submitted to a destination indicated by the request, wherein the second request is formatted as a cryptocurrency request for the cryptocurrency. A determination is made whether a reply to the second request from the destination is a cryptocurrency response for the cryptocurrency based on whether the response uses a protocol specified for a response that belongs to communication associated with the cryptocurrency. An intervention action is caused in response to a determination that the reply to the second request from the destination is a cryptocurrency response for the cryptocurrency.

Detection and mitigation of cryptojacking

A method and system for automatically classifying protected devices of a protected network to protection groups providing customized protection. The method includes accessing network flow information that includes network statistics processed from observed data obtained by packet interception devices, accessing at least one model that was trained using machine learning and a training data set of the network flow information to classify protected devices having addresses that correspond to destination addresses associated with the training data set to respective protection groups as a function of the network statistics that correspond to the training data set, and classifying a protected device that has an address that corresponds to a destination address associated with a portion of the network flow information to at least one of the protection groups using the at least one model and machine learning and as a function of the network statistics that correspond to the portion of the network flow information.

The method and system are provided for monitoring a protected network for strain. The method includes receiving a learned model having clusters of learning requests of learning network traffic observed during non-strain operation of the protected network, observing network traffic, classifying each of the traffic requests with one of the clusters based on fields of the traffic request and fields used for clustering the learning requests, determining an analysis response time for respective traffic requests associated with the classified traffic requests, determining an analysis response time characteristic per cluster based on an analysis response time associated with the respective classified traffic requests classified with the cluster, determining a difference per cluster between the analysis response time and the learning response times associated with the cluster, and notifying a mitigation device when the difference determined for enough of the clusters exceeds a predetermined threshold.

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Ypsilanti, MI, United States of America

Sean O'Hara